Gustaf dillberg and parnell rabbidge



(No Model.)

G. 'DILLBERG & PLRABVBIDGE. v TELEPHONE SYSTEM.

Patented July 27, 1897.

NITED STATES I KGUSTAF DILLBERG AND PARNELL RABBIDGE, OF SYDNEY, NEW

. WALES.

PATENT 'QFFICE SOUTH TELEPHONE SYSTEM;

SPECIFICATION forming part of Letters Patent NO. 586,993, dated July 27,1897. Application filed September 9, 1895. Serial No. 562,001.. (Nomodel.)

To all whom it may concern.-

Be it known that We, GUSTAF DILLBERG and PARNELL RABBIDGE, subjects ofthe Queen of Great Britain, and residents of Sydney, New South Wales,have invented certain new and useful Improvements in TelephonicInstruments Designed for Use on Poorly-Insulated Lines, such as theexisting wires of an ordinary wire fence, of which the following is aspecification.

The object of this invention is to produce a simple and effectivetelephonic instrument whereby loud and satisfactory speaking may beobtained. To accomplish this object We proceed as follows and as shownin the accompanying drawing, in which Y Z represent two separatetelephonic stations connected'together by line-wire L.

A and A represent calling apparatus; B and B, batteries; E, earth; H andH, rocking lever-switches and receiver-hooks K and K, relay-armatures; MN and M N, coils of wire surroundingiron cores P and P; R and R,receivers; T and T, transmitters; a b cc and a b c e, contact-points; dand cl, centers for 1-1 and H. f and f, are press-buttons connected to Hand 1-1, respectively.

WVhen Y desires to call Z, the button fis pressed against contact 0,thereby bringing battery B in circuit "with line L. The current afterpassing along same travels through receiver B into coils M and N'- toearth, thereby magnetizing core P, which attracts armature K, andconsequently connects K with contact 0, thereby establishing a localcircuit at Z-viz., battery 13 is enabled to supply current through d h aand bell A K and c to earth, consequently ringing the bell A. v

When Y has called Z by ringing his bell A, as already described, Z willpress his button f, thereby notifying Y that he is in attendmice byringing bell A, as already described. lVhen Y and Z lift theirrespective receivers R and R ofi the respective receiver-hooks H and H,the bells A and A are cut out of the circuits and the speaking circuitis established, because 11 and H leave contacts a and a and make contactwith b and 1), respectively. The current from batteryB will now passthrough H, b, T, and N to E, and from B, through H, b, T, and N, to E,consequently forming two separate local circuits,

We have found this system to be particu-' larly efficient on a leakyline-such, for instance, where the wires of fences have been utilized asthe line-wires, the current leaking away at the parts X X, where thewires are attached to the fence-posts.

Having now described our invention, what we claim as new, and desire tosecure by Letters Patent, is-

1. In a telephone, the combination of the speaking-circuit, a core, thetwo coils thereon, the call-circuit, one of said coils being connectedin the speaking-circuit and the other in the local-battery circuit, thearmature of the call-circuit being arranged to be attracted by the saidcore to close the callcircuit, the said coils acting as an inductioncoilfor the speaking-circuit and as a relay for the call-circuit,substantially as described.

2. Ina telephone, the combination of the speaking-circuit, thecall-circuit, an induction-coil having its primary and secondary coilsin series inthe speaking-circuit and an armature controlled by saidinduction-coil to control the call-circuit, substantially as described.

In witness whereof we have hereunto set our hands in the presence of twoWitnesses.

GUSTAF DILLBERG. PARNELL RABBIDGE. WVitnesses:

- W. WALKER,

U. W. ALEXANDER.

